LOCAL / ASoC: samsung: Add Samsung Low Power Audio Subsystem driver

This patch adds LPASS driver. The LPASS (Low Power Audio Subsystem)
is a special subsystem that supports audio playback with low power
consumption.

Signed-off-by: Inha Song <ideal.song@samsung.com>

4 files changed, 150 insertions, 0 deletions

diff --git a/sound/soc/samsung/Kconfig b/sound/soc/samsung/Kconfig
index e0244fe4c531..6fd4c9f1940a 100644
--- a/sound/soc/samsung/Kconfig
+++ b/sound/soc/samsung/Kconfig
@@ -33,6 +33,9 @@ config SND_SAMSUNG_SPDIF
 config SND_SAMSUNG_I2S
 	tristate
 
+config SND_SAMSUNG_AUDSS
+	tristate
+
 config SND_SOC_SAMSUNG_NEO1973_WM8753
 	tristate "Audio support for Openmoko Neo1973 Smartphones (GTA02)"
 	depends on SND_SOC_SAMSUNG && MACH_NEO1973_GTA02
@@ -241,5 +244,6 @@ config SND_SOC_SAMSUNG_TM2_WM5110
 	select SND_SOC_MAX98504A
 	select SND_SOC_WM5110
 	select SND_SAMSUNG_I2S
+	select SND_SAMSUNG_AUDSS
 	help
 	  Say Y if you want to add support for SoC audio on the TM2 board.
diff --git a/sound/soc/samsung/Makefile b/sound/soc/samsung/Makefile
index c15a7596f782..16ab0d05bfa7 100644
--- a/sound/soc/samsung/Makefile
+++ b/sound/soc/samsung/Makefile
@@ -8,6 +8,7 @@ snd-soc-s3c-i2s-v2-objs := s3c-i2s-v2.o
 snd-soc-samsung-spdif-objs := spdif.o
 snd-soc-pcm-objs := pcm.o
 snd-soc-i2s-objs := i2s.o
+snd-soc-lpass-objs := lpass.o
 
 obj-$(CONFIG_SND_SOC_SAMSUNG) += snd-soc-s3c-dma.o
 obj-$(CONFIG_SND_S3C24XX_I2S) += snd-soc-s3c24xx-i2s.o
@@ -18,6 +19,7 @@ obj-$(CONFIG_SND_SAMSUNG_SPDIF) += snd-soc-samsung-spdif.o
 obj-$(CONFIG_SND_SAMSUNG_PCM) += snd-soc-pcm.o
 obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-i2s.o
 obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-idma.o
+obj-$(CONFIG_SND_SAMSUNG_AUDSS) += snd-soc-lpass.o
 
 # S3C24XX Machine Support
 snd-soc-jive-wm8750-objs := jive_wm8750.o
diff --git a/sound/soc/samsung/lpass.c b/sound/soc/samsung/lpass.c
new file mode 100644
index 000000000000..e93e65a107d3
--- /dev/null
+++ b/sound/soc/samsung/lpass.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics Co., Ltd.
+ *	Inha Song <ideal.song@samsung.com>
+ *
+ * Low Power Audio SubSystem driver for Samsung Exynos
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <sound/soc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "lpass.h"
+
+#define EXYNOS5433_PAD_RETENTION_AUD_OPTION_OFFSET	0x3028
+#define EXYNOS5433_INITIATE_WAKEUP_FROM_LOWPWR_MASK	BIT(28)
+
+static struct lpass_info {
+	struct platform_device	*pdev;
+	void __iomem		*reg_sfr;
+	struct regmap		*reg_pmu;
+};
+
+static void lpass_enable(struct lpass_info *lpass)
+{
+	if (!lpass->reg_pmu)
+		return;
+
+	/* Unmasks SFR, DMA, I2S Interrupt */
+	writel(LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S,
+	       lpass->reg_sfr + SFR_LPASS_INTR_CA5_MASK);
+
+	writel(LPASS_INTR_DMA | LPASS_INTR_I2S | LPASS_INTR_SFR,
+	       lpass->reg_sfr + SFR_LPASS_INTR_CPU_MASK);
+
+	/* Active related PADs from retention state */
+	regmap_write(lpass->reg_pmu,
+		     EXYNOS5433_PAD_RETENTION_AUD_OPTION_OFFSET,
+		     EXYNOS5433_INITIATE_WAKEUP_FROM_LOWPWR_MASK);
+}
+
+static int lpass_probe(struct platform_device *pdev)
+{
+	struct lpass_info *lpass;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct resource *res;
+
+	if (!np) {
+		dev_err(dev, "Failed to get DT node\n");
+		return -ENODEV;
+	}
+
+	lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
+	if (!lpass)
+		return -ENOMEM;
+
+	lpass->pdev = pdev;
+	platform_set_drvdata(pdev, lpass);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Failed to get SFR address\n");
+		return -ENXIO;
+	}
+
+	lpass->reg_sfr = devm_ioremap_resource(dev, res);
+	if (IS_ERR(lpass->reg_sfr))
+		return PTR_ERR(lpass->reg_sfr);
+
+	lpass->reg_pmu = syscon_regmap_lookup_by_phandle(np,
+							 "samsung,pmu-syscon");
+	if (IS_ERR(lpass->reg_pmu)) {
+		dev_err(dev, "Failed to lookup PMU regmap\n");
+		return PTR_ERR(lpass->reg_pmu);
+	}
+
+	lpass_enable(lpass);
+
+	return 0;
+}
+
+static const struct of_device_id lpass_of_match[] = {
+	{ .compatible	= "samsung,exynos5433-lpass", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, lpass_of_match);
+
+static struct platform_driver lpass_driver = {
+	.driver = {
+		.name		= "samsung-lpass",
+		.owner		= THIS_MODULE,
+		.of_match_table	= lpass_of_match,
+	},
+	.probe	= lpass_probe,
+};
+
+module_platform_driver(lpass_driver);
+
+MODULE_AUTHOR("Inha Song <ideal.song@samsung.com>");
+MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem Interface");
+MODULE_LICENSE("GPL v2");
diff --git a/sound/soc/samsung/lpass.h b/sound/soc/samsung/lpass.h
new file mode 100644
index 000000000000..137705bb189f
--- /dev/null
+++ b/sound/soc/samsung/lpass.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics Co., Ltd.
+ *	Inha Song <ideal.song@samsung.com>
+ *
+ * Low Power Audio SubSystem driver for Samsung Exynos
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#ifndef __SND_SOC_SAMSUNG_LPASS_H
+#define __SND_SOC_SAMSUNG_LPASS_H
+
+/* SFR */
+#define SFR_LPASS_INTR_CA5_MASK	(0x48)
+#define SFR_LPASS_INTR_CPU_MASK	(0x58)
+
+/* SW_RESET */
+#define LPASS_SW_RESET_CA5	(1 << 0)
+#define LPASS_SW_RESET_SB	(1 << 11)
+
+/* Interrupt mask */
+#define LPASS_INTR_APM		(1 << 9)
+#define LPASS_INTR_MIF		(1 << 8)
+#define LPASS_INTR_TIMER	(1 << 7)
+#define LPASS_INTR_DMA		(1 << 6)
+#define LPASS_INTR_GPIO		(1 << 5)
+#define LPASS_INTR_I2S		(1 << 4)
+#define LPASS_INTR_PCM		(1 << 3)
+#define LPASS_INTR_SB		(1 << 2)
+#define LPASS_INTR_UART		(1 << 1)
+#define LPASS_INTR_SFR		(1 << 0)
+
+#endif /* __SND_SOC_SAMSUNG_LPASS_H */